The first group of 5 patients will receive a starting dose of 0.05 mg/kg, administered every 4 weeks (for this study, 1 month is defined as 4 weeks). Based on the assessment of the dose response in this initial group of 5 patients, it is recommended the starting dose in subsequent patients be increased to 0.075 mg/kg. The individual dose of AF37702 Injection will be modified based on hemoglobin levels. Dose adjustments will be made in order to achieve and maintain hemoglobin in the target range of 10.0-12.0 g/dL (see Section 5.4.1). The frequency of dosing may be decreased and dosing ultimately discontinued if Hgb is maintained within the target range. Due to the lack of treatment options in this population, more frequent dosing is justified in cases of a suboptimal response. If the Investigator determines that a patient has a suboptimal response despite dose increases, the frequency of injections may be increased up to once every other week, but the total dose may not exceed 0.35 mg/kg every 4 weeks.